Bulk materials, particularly but not exclusively food products of different types, are often transported and stored in large plastic or other containers. The containers, sometimes referred to as intermediate bulk containers (IBCs), typically have a capacity of 55 gallons to 330 gallons, the chosen size depending on content, transportation, storage site and other factors. Materials shipped in such bulk containers typically include specialty chemicals including adhesives or solvents, and food products such as juice concentrates or tomato pastes.
After initial manufacture of the material and deposit into the container, the containers are sealed to prevent leakage and contamination by chemicals, bacteria or other influences. The container usually includes an integral spout of some type, to which a dispensing valve may be attached to deliver the bulk material into smaller containers, into lead-off hoses, or otherwise.
Once the material is manufactured and sealed and the container is delivered to a site, the bulk container must be readied to deliver the contents. This usually involves attaching a valve to the spout, by snap-on, screw or other means. Since most containers attempt to preserve the sanitary state of the spout and contents by means of a breakable or frangible membrane across the spout, it is necessary to puncture the membrane to allow removal of the bulk material.
Known valve systems do not generally puncture the spout seal in a thorough, consistent and clean manner. It is known, for example, to attach a protruding nail or spear to an end of the valve which tears through the sealing membrane. This type of structure may be seen, for example, in the Drum Master product of Waddington & Duval, or in the 2" PVC valve product of Magic Plastics. However, those types of puncture devices pierce the membrane imperfectly, leaving large sections or flaps of the membrane which can interfere with the flow of the bulk material out of the container, or possibly break off and contaminate the material. Other sharp, protruding members generally suffer the same disadvantages.
Besides engagement with the spout, many known valve devices for bulk applications include a valve diameter of only a relatively narrow size, sometimes 2" or less, and usually narrower than the diameter of the spout itself. The total volume that the valve can conduct is therefore reduced. The valve action itself may involve a ball (or gate) valve, butterfly valves, or valving of other types, such as that reflected in Valteer products by Waddington-Duval, or an in-line, butterfly valve such as that in the 2" PVC valve by Lasco. Again, however, known designs make somewhat inefficient use of the possible volumetric capacity of the valve.
This means among other things that some bulk materials, particularly granular or particulate bulk materials, can not be made to flow, or flow very readily, from the large container out through the spout and into a smaller container.
Furthermore, may valve devices intended for bulk applications do not attempt to provide a good seal against oxygen, bacterial, chemical or other contamination. Valves, for example, reflected in the PVC I model by Spears or the Multi-Meter model by Rieke (Auburn, Ind.) do not include any sealing rings. O-rings or other sealing devices when provided on known devices may not fit precisely enough to assure a true bacteriological seal, which can compromise the entire contents of the bulk container once tapped.
It also the case that known valve devices are relatively large, heavy, and expensive. A typical valve design suitable for general purpose bulk use may typically cost between $10 and $40, which in bulk applications involving mass production and shipping may not be economical. A typical valve design also may weigh up to three pounds, or more, making attachment and handling more difficult.